A Chinese study has found superiority of nasal high-frequency oscillatory ventilation (NHFOV) superior to other respiratory support methods for avoiding re-intubation among preterm babies.
“To our knowledge, this is the first study comparing nasal high-frequency oscillatory ventilation (NHFOV) with NCPAP as post-extubation respiratory support modes in preterm infants with neonatal ARDS,” explained lead investigator Dr Yuan Shi, department of neonatology, Children’s Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China. “Usually, one of the most important causes of reintubation is difficulty in clearing the partial pressure of carbon dioxide (PCO2). We found that NHFOV was superior to NCPAP in reducing PCO2 levels.”
Invasive ventilation remains one of the cornerstones of reducing neonatal mortality in preterm infants with respiratory distress syndrome (RDS) and acute respiratory distress syndrome (ARDS). RDS refers to breathing problems usually caused by lung immaturity due to premature birth. ARDS is an emergency medical condition, usually with acute onset, with symptoms similar to those of RDS; it may be caused by “clinical insults” such as inhalation of toxic chemicals, inhalation of vomit or meconium, lung inflammation or injury, pneumonia, or septic shock. No matter what the cause of respiratory dysfunction, invasive ventilation can increase the risk of ventilator-associated lung injury, which may result in bronchopulmonary dysplasia (BPD) and subsequent neurologic impairment, especially in infants who require repeated or prolonged intubation. Therefore, early weaning from invasive ventilation is key to reduce these risks and is a primary goal for neo-natalogists.
NCPAP is a widely used therapy to improve ventilation in preterm infants but is not successful in avoiding reintubation in all infants. The new NHFOV technique was anticipated to improve outcomes by combining the advantages of NCPAP with those of high-frequency oscillatory ventilation (HFOV). Like NCPAP, NHFOV is non-invasive, but it also offers improved CO2 removal and increased functional residual capacity. The superimposed oscillations of NHFOV are thought to help avoid gas trapping and upregulate mean airway pressure (MAP).
This was a single centre, randomised, controlled trial that enrolled 206 preterm infants born at less than 37 weeks’ gestational age who were ready for extubation. The babies were randomised into two groups of 103 to receive either NHFOV or NCPAP treatment. Of these infants, 61.7% were diagnosed with RDS, 25.7% with ARDS, and 12.6% with both RDS and ARDS. Data were analysed for the overall group, as well as for those who were preterm (born at 32-36 weeks’ gestation) or very preterm (less than 32 weeks’ gestation).
The rate of re-intubation in the group receiving NCPAP was more than twice as high compared to infants who received NHFOV (34.0% vs 15.5%), especially in the very preterm group or those with ARDS or combined ARDS/RDS, but not in those with only RDS. After six hours of extubation, the PCO2 levels in infants treated with NHFOV were significantly lower than those treated with NCPAP.
Infants treated with NHFOV were also able to leave the hospital in fewer days than those who received NCPAP. The only adverse events reported in the NHFOV group were nasal trauma and intestinal dilation.
Two international randomised controlled trials are ongoing to establish the clinical superiority of NHFOV compared to other respiratory support methods for avoiding re-intubation in this fragile group of preterm babies.
Background: Nasal high-frequency oscillatory ventilation (NHFOV) has been described as supplying the combined advantages of nasal CPAP (NCPAP) and HFOV. However, its effect on preterm infants needs to be further elucidated. Our objective was to assess whether NHFOV could reduce intubation and PCO2 levels as compared with NCPAP during the post-extubation phase in preterm infants.
Methods: This was a single-center, randomized, controlled trial, and it was registered at clinicaltrials.gov (NCT03140891) and conducted between May 2017 and May 2018. Ventilated infants born at less than 37 weeks’ gestational age and ready to be extubated were included and randomized to either the NHFOV or NCPAP group. Primary outcomes were the incidence of reintubation within 1 week and the PCO2 level within 6 h.
Results: A total of 206 preterm infants were included. Of them, 127 (61.7%) were diagnosed with respiratory distress syndrome, 53 (25.7%) with ARDS, and 26 (12.6%) with both respiratory distress syndrome and ARDS. Comparing with NCPAP, NHFOV significantly reduced the reintubation rate (16:87 vs 35:68; 95% CI, 0.18-0.70; P = .002), especially in the subgroup with a gestational age of ≤ 32 weeks (12:34 vs 25:20; 95% CI, 0.12-0.68; P = .004). The PCO2 level was also significant lower in the NHFOV group (49.6 ± 8.7 vs 56.9 ± 9.9; 95% CI, –9.95 to –4.80; P = < .001). Moreover, NHFOV significantly reduced the reintubation rate in preterm infants with ARDS (10:33 vs 21:15; 95% CI, 0.08-0.57; P = .002).
Conclusions: NHFOV was shown to be superior to NCPAP in avoiding reintubation, especially in very preterm infants and those infants diagnosed with ARDS.
Long Chen, Li Wang, Juan Ma, Zhichun Feng, Jie Li, Yuan Shi